Technology Field
The invention relates to a server and, in particular, to a server that provides a better expansion card performance.
Related Art
Currently cloud information and application can be seen everywhere in daily life, and the developments of different services and network-connected devices make the data amount grow. Therefore, servers play a very important role behind the whole cloud industry.
Presently the demand for server functionality increases, and thus it is desired that expansion cards with best performance can be provided within limited space. Expansion cards can be divided into four types: low profile, FH/FL, FH/HL and HH/FL. FH means full height or standard height, FL means full length, HL means half length, HH means half height, and low profile means half height and half length. Generally speaking, the larger area, the better performance of the expansion card.
An 1U server has many PCI-E lanes, but in view of the space limitation the PCI-E lanes cannot be fully utilized. This results in a lower system performance although the CPUs are fast. Take the Dell R620 server supporting the largest number of I/O cards so far as an example, it has two CPUs and can accommodate more expansion cards. Its space arrangement allows it to accommodate three low profile expansion cards and one Mezzanine expansion card, which cards use 48 pairs of PCIe Gen3 signals. Since one CPU can handle 40 pairs of PCIe Gen3 signals, bandwidths of 32 PCI-E lanes are wasted. Therefore, the performance of the numbers of types of the expansion cards mentioned above cannot fulfill the market demand. Therefore, how to provide a server with higher performance becomes an urgent problem to be solved.